Let-off mechanism for looms



'Mareh 4, 1930. H. A.' DAVIS 1,749,131

'LET-OFF MECHANISM FOR LOOMS Filed March 26, 1927 3 Sheets-Sheet ll March 4, 1930.

H. A. DAvls LET-'OFF MECHANISM FOR LOOKS Fl'ed arch 26. 1927 3 Sheets-Sheet 2 March 4, 1930. H. A. DAvls 1,749,131

LET-OFF MECHANISM FOR LOOMS Filed March 26. 1927 I 3 Sheets-Sheet 3 Fig-4..

Invenor. Harry A. Davls 'i r`This invention relatesto letief meel@ mism for a: loom havin-g two Warp beams, Such,V

. y i The object oii ther invention avlet-oii' mechanism whiehwill ast automatif I PatenteclkMar. 4, 1930 l Awill oir-rice f i ELTON., 0F. HoreDALE, IMassa.oiaUsET'rs. A, ooRPoRATIoN ori/LAINE "Lumpur ivrEoHnNisM-roir YIioogMsy fork exampleyas a lbroad or Wide loom.Y when@v the` Warp is ranged in' axlalgallgnment.

' Voallyrto; equalizethe'tens-ion on thewarp on throughout the .entire- Warp kSheetf-bothbeams@ and thusV to equalize "thet-,ension s The; ob 'eot Aoi the invention` is further to. provide suoli l arletfzoii' :me,ohanismy thus equal,-

i'zingytheftension on the warps yon both beams. in which the let-o?V movement shall,l be oon? trolled; in.- proportion; both to thefwarp ten.-

ysion yandato the. amountof; yarn on k*the 'beams or tolthefvarying diameter of the warpkmassl y on .thebeamsg`- thusenabling thewarprtension i .i lprovide 'in1 such ailet-oimechanism 'imeans i direetionbyr'hand7 with-the tension ony the kwarpbeamsremaining;equalized tope maintained.;'constant'. ateaeh pick( f'llhe; objectxof theiinvention is further to wherebyboth; beams` may be rotated in either 'The Object ofltheinvention is further-to provide such a; letfoii mechanismywithfan rin- @Wh'eelwheri desired. l f f v Y. The object ,of ythe invention 'Y eluded @nach andk hand sheer byfwhmh uw aetuating llet-off l member and thefhand; 'wheel may be :Connectedand disconnectedaby; the

, clut-ehthusto placethe rotary movement of l the warp beamsfunder the control oi thehand 4 is further to lprovidesueh a let-oi mechanism which mayY` v readily be; embodied in existing looms..-

Y These; and` Yother.L objects I and? features :oi

thev invention will;= appear more ffully from', the

i accompanying: deseriptionandi- 'drawingsv and? willi beipartieulanly pointed-out in theglams. fIn the lpre'ferred Construction illustrated as me-embodiment ofthe inventionthe priniple" ofthewell known-Draper Roperletmi f mechanism, such asshownfinfPatent lNo;v 6472's' 45 81a@allenarsiit.,1900;is1ie1izeeand this mechanism ,and the, general; constitu@ f tonjandioperatolfl" ,0f @Wilde or broad 1.90m

f aire ,bO .WG111 known and, amiliar to those Skill'esin the est, it iSeOnlv 11e-cessera here te illustratey and describeindetail,thosefeatures I-ided. between two;v beams' aris tdyprovde of oonstrution in ywhich one preferredk form ofthe inventionmay be` embodied.

Inthe'drawings:

Fig., l is a, sideelevation`- partially broken away of the rear-ofthe loom.

Eig.. 2f is a.y top planview of tlieright-hand portion of the constitu'ationy shown in. Eig. 1. y Fig, 3 isa view partially broken away and partially in vertical section looking from the f ronttowardf'the rear portionlof the loom.

loom are providedk withy Suitable bearingsv 3.

in which, together with: anintermediate bearingY a, are supported the gndgeonsf of tho two` axially aligned. Warp beams 6 and 7.

rEhese;Warpbeams are of therusual construe tion, but Withfthe warpfbeamzprovided preferably onthefhead adjacent the loom sidel with the largey gear 8l rigidly secured` thereto and withfthewarpv beam. Z on theheady adja-y cent the loomzside`2; provided With'the large gear 9 rigidlyseoured thereto.A

A whiproll 10of-r the usualtype extends across above thevtwobeams and is journalled in arms 11 projeetifngfromthe shaft l2journailedy inY bearing bracketsl3 `on the loom sides. At the left-hand side this; shaft is providedfwith a radially extendingT arm 14. The sheet of warps l5. extends from thek barreisl of both. beams (Sand 7 up. over this whip roll 10y andthence forwardly throligh the usual shedffoiming mechanism and toVV the usual take-unrollatthe front ofthe loom.

` It is obvious that the tension upon the warp, thus divided betweenl the two. beams 6 and 7, must, be equalized throughout during the-entire weaving operation-or else there will be a-,variation in, thefoharaeter and quality fofythe. cloth at diiieren'ty portions of its width. lIt, is alsoobvious that the tension on the. Warpsvmust remainoonstant at each Vpiek or at correspondingperiodsiiteach oycle of thez weaving operation notwithsta;iding'-l the continuallydegreasing diameter. of the'warp l.; maar A. DAVIS, 0F' 'iioiEDALEQ lvIeSSACHSETTa,AssIGNom Tos DRArER' CORPORA- Loo l and that consequently as the weaving oper-A jas mass on the warp beams as the weaving operation proceeds, o r else there will be a variation in the character and quality of the cloth Y lengthwise. The present invention has for its ultimate purpose the securing of both of' these results. It` is assumed that the two beams when placed in theloom will have substantially the same diameter of warpy mass ation proceeds, the diameter of the warp mass on both beams will decrease at the same rate.

.In thek preferred form of the present invention illustrated, as in the Draper Roper let-off above referred to, the movement ofthe whip roll shaft 12,.due to the variation in tension on ythev warp at each pick, and the position` of an arm 16 determined by 'the ,diaineter, of the warp mass on one ofthe `beams i A Y* are utilized to controltheV extent of the letolf of the warps `at eachpick.

The ymain elements `of construction leinbodyinga preferredvform'of the invention may conveniently belocated on aframework attached to and projecting from one of-tlie sideframes of the loom such as the side frame 1, thus enabling thel mechanism readily to be applied to existing looms. f

A bracket 17 ,'s shown secured by the bolts 18 to the side frame l and projects laterally therefromy just beneath the gudgeon 5 ofthe warp beam 6. Another bracket 19 is simi-- larly secured to the side frame V1 and pro-,j

jects laterally therefrom near the bottom of the loom. These brackets at their outer ends are rigidly connected by a post 20., A bearing bracket 21 is rigidly secured to the post `2O 'and projects rearwardly therefrom midway between the outer ends of thebrackets 17 and 19. A shaft 22 extends Vacross the loom and has its bearing at one end in the side frame 2 and at the otherend inthe supporting bracket 21. This shaft has 'secured thereto a pinion 23 meshing with a gear 9 of the warp .beam 7. `A sleevey 2 4 is journalled on this shaft, has abearing at 25 in the'side frame 1 and has secured theretov a Vpinion 26, similar to the`pinion23, which meshes with the-gear 8 ofthe warpI beam 6. An internal driving gear 27 has its hub 28 journalled on the shaft'22. A hand wheel 29 havinga rim 30 by whichit may be manually'operated has of the hand wheel'. These pinions meshl :with j both members of a pair of bevel gears 3 5 Vand 36. The bevel'gear 35 issplined at 37 to the shaft 22, while the bevel gear 36 has ahub journalled on the shaft 22 and elongated Vto form the sleeve 24 to which is splined at 38 the pinion 26. It will thus be seienl that when the gear 27 is clutched to the hand wheel and is rotated in either direction, it will drive differentially, through vthe mechanism just v described, thetwo warp beams and thus continuously equalize the `tension on the warps extending from the'two beams. Y Y f v The gear 27 ywhich thus drives 'differentially the two warp beams is a positively actuf i Vated let-off member and its rotary movement is controlled in accordance with"Y the prinj ciple of the Draper Roper let-off mechanism.

It is frequently desired to rotatethewarp beams by hand, as in the case of a pick-out, j

or whenever required in the'foperation ofthe loo'ml Thishand rotation of thewarp beams is provided for by the hand wheel 29, theretation of Which, vit willjbeobserve'd, isalso Y imparted differentially to the two warpbeams vso as to equalize the tension thereonund'er all conditions. VAA manually controlled `clutch is provided for connecting and disconnecting the let-olf member or gear andthe hand ik wheel 29. In the construction illustrated, a clutch sleeve ,39 is splined at 40 to the huby 28 of the gear 27. A helical spring 41-on the hub 28 between the sleeve 39'and the gear 27 acts normally toy force this clutch sleeve vinto engagement with the yhand wheel, inter-y locking projections being provided, between the adjacent surfaces of the clutch sleeve and the hand wheel, asshownfati42. Theclutch Vsleeve has its periphery groove'd at 43 and Y v y this groove is engaged by'the'arms 44 of a bifurcat'ed bell'crank lever having awfulcrumed shaft 45 journalled ina bearing sleeve 46 projecting` from the'bracket 19. The shorter arm 47 J of this Vbellcrank''lever extends laterally and is connectedby alink 48jto a` treadle 49 fulcrumed at50 lin'an arm 51 projecting downwardlyfroin the bracket 19.

It will thus be seen that the operator bypressl of the hand-wheel 30 and may effect the coning his foot on the treadle 49 may readily V disconnect the clutch andthus placethe rotationV ofjt-he'warp beams under the control4 i110 i nection of the clutchk by removing his foot from the treadle 49 and allowingtlie spring 4l to'act. A j j The gear 27 is rotated by'a speed reducing gear from the ratchet wheel-52.l yThe hub l53 v of this ratchet wheel is vjournalled on the l' shaft 22 and extends within the internal gear. An 'eccentric54is formedr integrally with or f securedto the-'hub 53 and has' journalled thereon the'r gear 55 having a less-numbery of teeth and being of smaller diameter than the j Y i gear 27 .and meshing therewith. An arm 56 extends radiallyof the shaft 22 adjacent'the Y -f gear 55.; At its'oute'r end this armis slotted at57'to slide on a shaft 58journalled' an elongated bearing sleeve y59 formed 'ony the lower` part of a bracket GOfc/lampedfby bolts 61 to, and depending from, the side frame 1. At the other end the arm 56-is bifurcatedto '64fprojectingfromthe facefof the gear 55;' Thus it will'be seenthat rotationfof thev Vratchet 'wheel' 52 willfimpart throughthe l'eccentric 54 a circular'movement to the gear `,"itsrotationbeing prevented by the armv 56 while the geartravels 'along' the internal gear 2.7', rotating the latter in the same diu rectiongbut owing'to the difference inthe gear Y l numberoffteeth of .theftwo gears,"the internal will rotate rmore slowlythan the gearr lkTheV extent fof movement' imparted tothejratchetjwheel `52 to'letfoff the warp 'at' eachy pick is here under the control both .v of the'tensionY on the warp's, asl indicated by the extent of movement 'ofr the whip roll shaft ,12, andof the amount of' -warp on the beams .or Athe 'diameter of they .warp mass at `each pick. QThe rotary/.movement thus imp'arted'pund'er these controls to thelratchet 52. a5

` j nismffjust describedand by the'ratio ofthe'A is rednce'd bythespeed reducing gear mecha'.-

f pinions26 and123fto the gea-rs 8 and 9 so n' thatv the warp quiredy extent.

as Th beams are rotatedY to the reg' y p "elmechanisni"'forljrotating the ratchet Wheel i 512, comprises e' Spring-Pressed PaWl pivote`d'onfa pawl'carryinglever 66 kfulcrumed on the shaft v22. f This pawl carrying leveris ,givenl its adw'fancingvr movementby r the" lay'and is always advanced "to the same 'p'oint'rjwhen once adjusted.. Its retracting vrin/ovenrient; which determines the lIiumberv of tefethffthus advanced', yis under the control jintgiyfof the movement of the whip ron 4o shaft `and vthe diaffeters ofthe warp'frnass on'theibeam.'` l 4 y ,f Since this mechanism is set well' out from u the sideof the loom .frame,` it isnecessary to proyide a suitable connection to the lay.

The'lay'rocker shaft 67 is shown provided'y with, an upward" projection 68,l preferably on theflayrocker` support 69. Aj'bracket 70 is securedA by bolts71tok the sideframe y1' and projects laterally therefrom. shaft'f72 journalled n'this bracket andcarries atfeach end rigidly secured theretov upstandingjarms 7 Siand 7 4. An upstanding`arm75 "is secured as by the bolt7 6 to the projection 68 and-a link 7 7ffi's"r pivotally'connected toftheupper end of this armf75 andtov theupperend of the arm 73.` Alink 78 is pivoted at 79 to the lower end of the pawl carrying lever 66 and .at its other 'end has adjustably secured thereto, as by the set screw 80, a slotted head 81` engaging a stud82 on theupper lend of 'the arm 74. It will thusbe seen that as the lay beats up,` rocking the shaft 67, these conlnections, will act to rock the pawl carrying I lever 66 `counter-clockwise and always ad-` vance the pawl 65 to the same extent. 1It will also be seen that' the slotted'head 81 permits the pawl to be retracted, upon the backward movement of the lay, to a variable extent and thus topass overa variable number of teeth of the ratchet wheel. A

yThe'arm'14 extending from the whip roll shaft 13 is vco'nnectedkby a link 83 to an arm 84 secured toashaft 85 journalled in the upstanding arms 86 of an vauxiliary bracket 87 mounted on the topfof the bracket 17. This shaft y85 yis yieldingly rotated against the'warp by va helical spring 88 on yone end ofthe shaft engaging at one end the arm 86 Aand at the other end a collarv 89 adjustable on 'the shaft;y VPowerful springs 90 on kthe link83extend between Vthe arm 14'and an abutment 91 secured to the auxiliary bracket 87. Collars 92 enable one or both of these` springs to lbe thrown into action and their force adjusted to produce a greater or less tension on the warp or pressure of the whip rolll() yagainst the warp. The outer end of `the-shaft l has secured thereto the hub 93 of an arml 94 which extends down alongside the vpa'wly carrying lever 66.` This arm 94 andtheopposed surface of the lever 66 are both longitudinally recessed or grooved at 95iand96f, respectively; Small rolls 97 pivotedinf alignment tothe upper end of an arm 98'v slide in'these grooves 95 `and 96.

Thisarm 98 is' oifset to avoid the shaft 22 and is pivoted at its lower end'y at 99 to an arm 100', the hub `of which is secured by a set screwy101` to the'en'dof the shaft 58. The opposite end of the shaft 58 has secured thereto 'thef arm 16 already mentioned and .the 'upper enlarged head* 102 of which is adapted to rest against the warpmass'on oney of the beams.v It will thus be seen that the tension on `the warpsf15 acts after each beat-up` to depress the whip roll, thus compressing the springs and rocking the arm 84. andconsequently the shaft 85 and the arm 94 forwardly; But, asthis arm 94 is connected by means of the rolls97 to the pawl carrying lever 66,the pawl 65'is retracted toy an extent depending upon 4the, tension on the warp. lheextent` of 'this retraction is further controlled bythe Vertical position of the rolls 97 and this vertical position depends upon the kposition of the arm 16 engaging the warp mass#A Asfthe diameter'of the warp mass decreases-the arm 16 swings rearwardly rocking the Shaft 58,1 lowering the arm 100 and*consequently the arm 98 in which the 'rolls97 are pivoted. The rearward limit of movementv of theactu'ating pawl 65 is deter'- mined bythe forward movement of the lay. Thus the extentf of movementof the actuating pawl is 'controlled both by the tension ter of the warp ony the warp andthe diame mass on the warp beam A suitable friction brake `103 is provided Engaging the IalChl'Wlleel .52 t0 prevent T0- ment of the actuating pawl. Having thus described the invention, what itation'thereof during'the retracting moveis claimedasnew, and desired to bevsecured yof yarn onth'e beams at each pick,

2. Let-o mechanism for a loom` having two warpbeams vcomprising the construction dened in claim l, in whichthe said manually controlled means connecting and discon-V nectingthe letoliv member and hand wheel comprises a clutch, a spring actingnormally tothrowthe clutchinto connecting position and a-lever manually operable in opposition to said spring. t f

3. Let-ofi mechanisnifor a loomhaving two warp beams comprising fa driving"gear,

a hand wheel,l a manually controlled clutch l for connecting and disconnecting the hand wheel to the drivin gear, a pair of gearsy driven dierentially y the hand wheel, driving connections respectively between the two beams andthel driven gears, means for positivelyrotating the driving gear to let ott" the warp, and means to vary the amountof said rotary vmovement ofthe driving gear in pro#V portionboth to the vwarp te'nsionf'and to the diameter of the warp mass at eachpick, the disconnection of the clutch enabling the two,

warp beams to be rotated in either direction by the hand wheelv throu'ghfthe,differential gearmeehanism. i l 1 4. Let-off ymechanism for a loom `having two'warp beams comprising a positively ro-y tated leteoi member, aghandrwheel rotatabley with the let-ot`f member, manually controlled means for connecting'anddisconnecting the let-oftl member andhand wheel, differential drivingy connections between the hand wheel and both beams whereby the tension on the warp-on both beams is continuously'equalized, and means to vary the amount Vofsaid rotation of the let-o member. v

Y5.. Let-off mechanism for afloomfhaving t two warp Vbeams comprising the construction defined in claim 4, in which the said manually controlled means connecting and disconnecting the let-o member and hand wheel "comprises a clutch, a'spring acting normally to throw the clutch into connecting position and a lever manually operable in opposition to said spring. f

f 6. '-Letofi mechanism for a loom having two warp beams comprising ai driving; gear, a. hand wheel, a manually controlled clutch for yconnecting and disconnecting the hand f wheel vto the vdriving gear,y a pair of `gears driven differentially by thehandwheel, drivf ing'l vconnections respectively between thetwo beams and the driven. gears, mea ns.forp0si` tively rotating the .drivinggear to'let-oil lthe warp, and means to. varythe amount ofsaid .rotary movement of the-'driving gear, the

disconnection of the clutch enabling the two Warp beamstobe rotated in either direction by unaV hand Wheel throught@ differential rgear mechanism. Y Y t 7 Let-offl mechanism( for ailoom having two warp beamscomprising differential driving connections for the'two beams, a hand wheel acting throughlfsaid connections to ro-V Y tate the beams manually with the tension equalized," 'and automatically controlled; ymeans acting. throughY said'connections/toy f rotate thevbeams and let off the warps 4on both beams with the tension equalized.

V8. Let-oit mechanism `for Va loom'havi'ng two warp beams and having theconstruction defined in claim 7, together with means for ential driving connections. v

9. Let-off mechanism-fora loom* having twowarp beamsand'having theconstruction vdisconnecting,saidautomatically controlled I means from, andtconnecting it to,vthe differ-V defined in claim`7, together withmanually operated means for disconnecting said auto-l maticallyy controlled Vmeans `from, and con.

necting it to, the differential; driving connections.

yl0. Let-.off mechanism for a yloom having twowarp beams andhaving the construction` i deiineduin claim.7, together with yielding p means acting normally rvto connect said: auto-V matically controlled meansl to the .ditl'eren tial'driving connections andmanually oper- Y able tofeifect disconnection'thereoi 1 1.`Letomechanism for a loom havingtwo `warp beams comprising a vpositively'- rotated let-0H4 member, a handwheel rotatable with the letoff member, manually controlled means vfor.connecting and disconnecting theV 'nol let-oit member a'ndhand wheel, differential driving connections betweenY Vthe hand wheel andbothffbeams whereby Vthe tension on'the warp onbeth beamsA l,continuously equalf` ized.

r Intestimony-whereof,l have signed my Y,

name to thisspeciiication. t t,

- f HARRYA. DAVIS'.l 

